The veronicellid slug Laevicaulis stuhlmanni aegypti Ali & Robinson (Family: Veronicellidae) is a new subspecies and record that had been discovered for the first timein garden in El Zamalek at Cairo governorate, Egypt.The main biological aspects of theveronicellid slug had been recorded i.e., incubation period, hatchability percentage, life cycle, oviposition, generation period as well as life span. These observations were recorded under laboratory conditions during slug's activity season starting from March till early December. Biology of veronicellid slug had not adequate study of their life cycle and behavior, especially for new subspecies record in the Egyptian environment. Self-fertilization is the normal breeding system for laying eggs; with big number of egg clutches, that makes the slug is a dangerous invader pest with population for attacking any new environment in the future.